[1/5] libfrog: add directory tree structure scrubber to scrub library

Commit Message

Darrick J. Wong July 2, 2024, 1:20 a.m. UTC

From: Darrick J. Wong <[e-mail]>

Make it so that scrub clients can detect corruptions within the
directory tree structure itself.  Update the documentation for the scrub
ioctl to mention this new functionality.

Signed-off-by: Darrick J. Wong <[e-mail]>
---
 libfrog/scrub.c                     |    5 +++++
 man/man2/ioctl_xfs_scrub_metadata.2 |   14 ++++++++++++++
 2 files changed, 19 insertions(+)

Comments

Christoph Hellwig July 2, 2024, 6:48 a.m. UTC | #1

Looks good:

Reviewed-by: Christoph Hellwig <[e-mail]>

Patch

diff --git a/libfrog/scrub.c b/libfrog/scrub.c
index baaa4b4d9402..a2146e228f5b 100644
--- a/libfrog/scrub.c
+++ b/libfrog/scrub.c
@@ -149,6 +149,11 @@  const struct xfrog_scrub_descr xfrog_scrubbers[XFS_SCRUB_TYPE_NR] = {
 		.descr	= "retained health records",
 		.group	= XFROG_SCRUB_GROUP_NONE,
 	},
+	[XFS_SCRUB_TYPE_DIRTREE] = {
+		.name	= "dirtree",
+		.descr	= "directory tree structure",
+		.group	= XFROG_SCRUB_GROUP_INODE,
+	},
 };
 #undef DEP
 
diff --git a/man/man2/ioctl_xfs_scrub_metadata.2 b/man/man2/ioctl_xfs_scrub_metadata.2
index 75ae52bb5847..44aa139b297a 100644
--- a/man/man2/ioctl_xfs_scrub_metadata.2
+++ b/man/man2/ioctl_xfs_scrub_metadata.2
@@ -148,6 +148,20 @@  that points back to the subdirectory.
 The inode to examine can be specified in the same manner as
 .BR XFS_SCRUB_TYPE_INODE "."
 
+.TP
+.B XFS_SCRUB_TYPE_DIRTREE
+This scrubber looks for problems in the directory tree structure such as loops
+and directories accessible through more than one path.
+Problems are detected by walking parent pointers upwards towards the root.
+Loops are detected by comparing the parent directory at each step against the
+directories already examined.
+Directories with multiple paths are detected by counting the parent pointers
+attached to a directory.
+Non-directories do not have links pointing away from the directory tree root
+and can be skipped.
+The directory to examine can be specified in the same manner as
+.BR XFS_SCRUB_TYPE_INODE "."
+
 .TP
 .B XFS_SCRUB_TYPE_SYMLINK
 Examine the target of a symbolic link for obvious pathname problems.